Be aware of bad posture, bad wrist angles, etc. Most people are all slumped over when they are relaxing in front of the TV.
I usually am standing or sitting on a stool. Can't play in my recliner or on the couch for the very reasons you describe. It begins to hurt if I do.
Hey, when growing up I always did my homework in front of the TV. No problem. Graduated in the top 20% with a 92 average. Also, did it in college and ended with a 3.2 GPR. Not bad.
However, today if my wife is watching one of her reality shows I'd rather go somewhere else. But that goes for anything else I might be doing besides playing bass as well. I hate those shows.